This invention relates to parking brake actuating mechanisms and particularly to such mechanisms, hereinafter being referred to as of the kind specified, comprising a first lever having a first contact zone adapted to engage a first brake shoe portion, said first lever being pivotally connected with a second lever, the second lever having a second contact zone adapted to engage a second brake shoe portion, pivoting of the first lever relative to the second lever being arranged to increase the effective length of the mechanism between the contact portions thus moving the associated brake shoe portions apart to engage the parking brake.
There is an increasing requirement in the industry to make the attachment of actuating cables to parking brake mechanisms a process which can be carried out on the vehicle assembly line without the need for the brake to be disassembled to give access to the internals of the parking brake actuating mechanism.
It is an object of the present invention to provide a parking brake actuating mechanism of the type specified in which the actuating cable can be engaged with the lever mechanism without requiring internal access to the associated drum brake.
Thus according to the present invention there is provided a parking brake actuating mechanism of the type specified in which the first lever includes an actuating cable abutment formation against which an actuating cable nipple on a free end of the cable is drawn to move the first lever hence operating the mechanism, the first lever also being of hollow form defining a guide passage through which the free end of the cable is directed from an aperture in the backplate of the associated brake to a location adjacent to the abutment formation to enable the nipple to be engaged with the formation
The cross-section of the guide passage formed within the first lever may have a cross section part of which allows the passage therethrough of the cable nipple and part of which is narrow and will not allow passage of the nipple, one end of the narrow portion of the passage forming the abutment formation against which the nipple is drawn after the free end of the cable has emerged from the passage.
The passage is preferably curved and the cable is arranged to deflect the cable towards the narrow portion of the passage as it is inserted through the passage so that when the free end of the cable emerges from the passage the nipple thereon is deflected towards and engages the abutment formation formed by the end of the lever which contains the narrow portion of the passage.
The first lever may also include a portion outside the passage which guides the cable from the passage towards the abutment formation.
The second lever may also be shaped to assist in guiding the nipple into engagement with the abutment formation when the nipple emerges from the passage.
A parking brake actuating mechanism in accordance with the invention is suitable for use in a normal drum brake or in a so-called drum-in-disc brake. Also, the mechanism may be engaged between portions of separate brake shoes or between different portions of a single curved brake shoe.